// 映射data
class Driver {
  constructor(vm, targetKey) {
    if(vm[targetKey]) {
      Object.keys(vm[targetKey]).forEach(key=> {
        Object.defineProperty(vm, key, {
          get() {
            return vm[targetKey][key]
          },
          set(newVal) {
            vm[targetKey][key] = newVal
          }
        })
      })
    }
  }
}
